Global Positioning System.

 The network formed by 24 navigation satellite orbiting the Earth is Global Positioning System (GPS). Through this network people can find their position on Earth. At height of 20000 kilometers (12500miles) this satellite of GPS makes orbit to earth. Satellites which are above the horizon are responsible to provide signals to GPS receiver. To find out how far GPS receiver is away from satellite , it uses information in each signal to work out. Information from at least three satellites are required to find out position of GPS on earth's surface. Latitude and longitude position on earth's surface of GPS are visible on screen of basic GPS receiver. Features of GPS varies from purpose of it's use. GPS designed for vehicles are built with advance receiver which show position on digital map. This receiver also shows extra information like length of journey, vehicle speed, traffic on route and etc. Some receivers gives warning if vehicle speed's goes beyond the limit for that road also it shows which route is best for journey and which should be selected at junction. Some receivers shows route in form of arrows directing towards way and they have synthesize voice which spokes route after some time of interval.